Spectral broadening of picosecond 1.06 μ pulse in KBr

Spectral broadening of picosecond 1.06 μ pulses in KBr crystal is measured. The electronic Kerr effects and avalanche ionization are employed to interpret the broadening and its upper limit at the Stokes side in KBr and NaCl.     

A study of the orientational drawing of monofilament Lavsan

A comparative study of two variants of the orientational drawing method for Lavsan monofilament is presented, i. e., the usual method of drawing in hot water, which depends on the difference in angular velocity of two rotating discs, and the traction method, in which the filament is drawn through the nozzle of a spinneret. The effect of drawing temperature on the physico-mechanical and structural properties of Lavsan monofilament studied, and possible differences in drawing mechanism between the two methods are considered.Mekhanika Polimerov, Vol. 1, No. 6, pp. 146–151, 1965     

Polymer Science Before and After 1899: Notable Developments During the Lifetime of Maurits Dekker

Several books have been published on the history of Polymer Science [1–5], and most of the post-1899 history parallels the lifetime of Dr. Maurits Dekker, who was born in Holland on March 18, 1899.     

Direct Synthesis of Multiplexed Metal‐Nanowire‐Based Devices by Using Carbon Nanotubes as Vector Templates

We present the synthesis of metal nanowires in a multiplexed device configuration using single‐walled carbon nanotubes (SWNTs) as nanoscale vector templates. The SWNT templates control the dimensionality of the wires, allowing precise control of their size, shape, and orientation; moreover, a solution‐processable approach enables their linear deposition between specific electrode pairs in electronic devices. Electrical characterization demonstrated the successful fabrication of metal nanowire electronic devices, while multiscale characterization of the different fabrication steps revealed details of the structure and charge transfer between the material encapsulated and the carbon nanotube. Overall the strategy presented allows facile, low‐cost, and direct synthesis of multiplexed metal nanowire devices for nanoelectronic applications.     

Accurate first-principles detailed-balance determination of auger recombination and impact ionization rates in semiconductors

The technologically important prediction of Auger recombination lifetimes in semiconductors is addressed by means of a fully first-principles formalism, based on precise energy bands and wave functions provided by the full-potential linearized augmented plane wave code. The minority carrier Auger lifetime is determined by two related approaches: (i) a direct evaluation within Fermi's golden rule, and (ii) an indirect evaluation, based on a detailed balance formulation combining Auger recombination and its inverse process, impact ionization, in a unified framework. Lifetimes determined with the direct and indirect methods show excellent consistency between them (i) for n-doped GaAs and (ii) with measured values for GaAs and InGaAs. This indicates the computational formalism as a new sensitive tool for use in materials performance optimization.     

Fluorinated nitrogen heterocycles via cyclization. III. 3-trifluoromethyl-1-(4-trifluoromethyl-2-pyridyl)-pyrazoles from fluorinated 1,3-diketones and 4-trifluoromethyl-2-hydrazinopyridines

Fluorinated 1,3-diketone compounds having the general structure CF₃COCH₂COR₁ underwent cyclization with 4-trifluoromethyl-2-hydrazinopyridines (IV) to give a series of 3-trifluoro-methyl-1-(4-trifluoromethyl-2-pyridyl)-pyrazoles (V). The hydrazinopyridine intermediates (IV) were prepared by conversion of 4-trifluoromethyl-2-pyridones (II) to the chloropyridines (III) followed by treatment of the latter with hydrazine hydrate.